What should the questioner do about her brothers' refusal to give her her rightful share of her mother's inheritance, and what is the solution to this problem?

Your brothers are not permitted to prevent you and your sisters from your legitimate Shar'i right to your mother's inheritance. Whoever does so has wronged himself and transgressed the boundaries of Allah. They must fear Allah and divide the inheritance as Allah has commanded. If they do not respond, then someone who can influence them should be brought in to mediate. Otherwise, you may take the matter to court. As for boycotting and abandoning them, this is not permissible for more than three days. Rather, you must maintain ties with them, for maintaining ties is not about reciprocating, and it is more conducive to harmony and affection.